FMGE brachial plexus upper limb nerve injuries important topics 2024 2025

ls -la /home/daytona/workspace/ 2>/dev/null || echo "workspace empty or missing"

mkdir -p /home/daytona/workspace/brachial-plexus-pdf && python3 -c "import repor…

~/brachial-plexus-pdf/generate_pdf.py

from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, PageBreak
)
from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import mm, cm
from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import ListFlowable, ListItem

# ── Output path ───────────────────────────────────────────────────────────────
OUTPUT = "/home/daytona/workspace/brachial-plexus-pdf/Brachial_Plexus_Upper_Limb_Nerve_Injuries_FMGE.pdf"

# ── Colour palette ────────────────────────────────────────────────────────────
DARK_BLUE   = colors.HexColor("#1a3a5c")
MED_BLUE    = colors.HexColor("#2e6da4")
LIGHT_BLUE  = colors.HexColor("#dce9f5")
ACCENT_GOLD = colors.HexColor("#e8a020")
LIGHT_GOLD  = colors.HexColor("#fdf3df")
LIGHT_GRAY  = colors.HexColor("#f4f6f8")
RED_WARN    = colors.HexColor("#c0392b")
GREEN_OK    = colors.HexColor("#1d7a3a")
WHITE       = colors.white
BLACK       = colors.black
TABLE_HDR   = colors.HexColor("#1a3a5c")
TABLE_ALT   = colors.HexColor("#eaf1fa")

# ── Document ──────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    leftMargin=18*mm, rightMargin=18*mm,
    topMargin=22*mm, bottomMargin=22*mm,
    title="Brachial Plexus & Upper Limb Nerve Injuries – FMGE Master Notes",
    author="Orris AI",
)

W = A4[0] - 36*mm   # usable width

# ── Styles ────────────────────────────────────────────────────────────────────
base = getSampleStyleSheet()

def style(name, parent="Normal", **kw):
    s = ParagraphStyle(name, parent=base[parent], **kw)
    return s

S = {
    "cover_title": style("cover_title", "Title",
        fontSize=26, textColor=WHITE, leading=32,
        alignment=TA_CENTER, spaceAfter=6),
    "cover_sub": style("cover_sub", "Normal",
        fontSize=13, textColor=LIGHT_BLUE, leading=18,
        alignment=TA_CENTER, spaceAfter=4),
    "cover_tag": style("cover_tag", "Normal",
        fontSize=10, textColor=ACCENT_GOLD, leading=14,
        alignment=TA_CENTER),
    "h1": style("h1", "Heading1",
        fontSize=15, textColor=WHITE, leading=20,
        backColor=DARK_BLUE, spaceBefore=14, spaceAfter=4,
        leftIndent=-4, rightIndent=-4,
        borderPad=6),
    "h2": style("h2", "Heading2",
        fontSize=12, textColor=DARK_BLUE, leading=16,
        spaceBefore=10, spaceAfter=3,
        borderPad=2),
    "h3": style("h3", "Heading3",
        fontSize=10.5, textColor=MED_BLUE, leading=14,
        spaceBefore=7, spaceAfter=2),
    "body": style("body", "Normal",
        fontSize=9.5, leading=14, spaceAfter=4,
        alignment=TA_JUSTIFY),
    "bullet": style("bullet", "Normal",
        fontSize=9.5, leading=13, leftIndent=14,
        bulletIndent=4, spaceAfter=2),
    "warn": style("warn", "Normal",
        fontSize=9.5, leading=13,
        backColor=LIGHT_GOLD, borderPad=6,
        textColor=colors.HexColor("#7a4800"),
        spaceAfter=6),
    "tip": style("tip", "Normal",
        fontSize=9.5, leading=13,
        backColor=colors.HexColor("#e8f5e9"), borderPad=6,
        textColor=GREEN_OK,
        spaceAfter=6),
    "quote": style("quote", "Normal",
        fontSize=9, leading=13, leftIndent=12, rightIndent=12,
        textColor=colors.HexColor("#444444"), fontName="Helvetica-Oblique",
        spaceAfter=4),
    "footer": style("footer", "Normal",
        fontSize=8, textColor=colors.HexColor("#888888"),
        alignment=TA_CENTER),
    "toc_entry": style("toc_entry", "Normal",
        fontSize=10, leading=16, textColor=DARK_BLUE),
    "section_num": style("section_num", "Normal",
        fontSize=9, textColor=MED_BLUE, leading=12, spaceAfter=1),
}

# ── Helpers ───────────────────────────────────────────────────────────────────
def H1(txt):
    return [Paragraph(f"<b>{txt}</b>", S["h1"]), Spacer(1, 3*mm)]

def H2(txt):
    return [Paragraph(txt, S["h2"]), HRFlowable(width="100%", thickness=1,
            color=MED_BLUE, spaceAfter=2)]

def H3(txt):
    return [Paragraph(f"<b>{txt}</b>", S["h3"])]

def P(txt):
    return [Paragraph(txt, S["body"])]

def Warn(txt):
    return [Paragraph(f"⚠ <b>Exam Trap:</b> {txt}", S["warn"])]

def Tip(txt):
    return [Paragraph(f"✔ <b>High-Yield:</b> {txt}", S["tip"])]

def Quote(txt):
    return [Paragraph(f'"{txt}"', S["quote"])]

def bullets(items):
    out = []
    for it in items:
        out.append(Paragraph(f"• {it}", S["bullet"]))
    return out

def sp(n=4):
    return [Spacer(1, n*mm)]

def hr():
    return [HRFlowable(width="100%", thickness=0.5, color=colors.HexColor("#cccccc"), spaceAfter=4)]

def table(data, col_widths=None, hdr_rows=1, alt=True):
    t = Table(data, colWidths=col_widths, repeatRows=hdr_rows)
    style_cmds = [
        ("BACKGROUND", (0,0), (-1, hdr_rows-1), TABLE_HDR),
        ("TEXTCOLOR",  (0,0), (-1, hdr_rows-1), WHITE),
        ("FONTNAME",   (0,0), (-1, hdr_rows-1), "Helvetica-Bold"),
        ("FONTSIZE",   (0,0), (-1,-1), 8.5),
        ("LEADING",    (0,0), (-1,-1), 11),
        ("ALIGN",      (0,0), (-1,-1), "LEFT"),
        ("VALIGN",     (0,0), (-1,-1), "MIDDLE"),
        ("GRID",       (0,0), (-1,-1), 0.4, colors.HexColor("#aaaaaa")),
        ("ROWBACKGROUNDS", (0, hdr_rows), (-1,-1),
            [TABLE_ALT, WHITE] if alt else [WHITE]),
        ("TOPPADDING",  (0,0), (-1,-1), 4),
        ("BOTTOMPADDING",(0,0),(-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 5),
        ("RIGHTPADDING",(0,0), (-1,-1), 5),
    ]
    t.setStyle(TableStyle(style_cmds))
    return [t, Spacer(1, 4*mm)]

# ── Cover page ────────────────────────────────────────────────────────────────
def cover_block():
    cover_bg = Table(
        [[Paragraph("<b>Brachial Plexus &amp;</b>", S["cover_title"]),],
         [Paragraph("<b>Upper Limb Nerve Injuries</b>", S["cover_title"]),],
         [Spacer(1,4*mm)],
         [Paragraph("Complete FMGE / NBE Master Notes", S["cover_sub"])],
         [Paragraph("Anatomy • Clinical Scenarios • Exam Traps • Quick-Reference Tables", S["cover_tag"])],
         [Spacer(1,8*mm)],
         [Paragraph("Compiled from Gray's Anatomy for Students • Miller's Review of Orthopaedics 9e •<br/>"
                    "Neuroanatomy through Clinical Cases 3e • Localization in Clinical Neurology 8e •<br/>"
                    "Schwartz's Principles of Surgery 11e • Bailey &amp; Love 28e • THIEME Atlas",
                    S["cover_tag"])],
        ],
        colWidths=[W],
    )
    cover_bg.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), DARK_BLUE),
        ("TOPPADDING",  (0,0), (-1,-1), 10),
        ("BOTTOMPADDING",(0,0),(-1,-1), 10),
        ("LEFTPADDING", (0,0), (-1,-1), 16),
        ("RIGHTPADDING",(0,0),(-1,-1), 16),
        ("ROUNDEDCORNERS", [6]),
    ]))
    return [Spacer(1, 20*mm), cover_bg, PageBreak()]

# ── Story builder ─────────────────────────────────────────────────────────────
story = []
story += cover_block()

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 1 – BRACHIAL PLEXUS FRAMEWORK
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("1. Brachial Plexus Framework")
story += P("The brachial plexus arises from anterior rami of spinal roots C5–T1 and organises "
           "into the following levels. Mnemonic: <b>Randy Travis Drinks Cold Beer</b> "
           "(Roots → Trunks → Divisions → Cords → Branches).")
story += sp(2)

plexus_data = [
    ["Level", "Components", "Key Notes"],
    ["Roots", "C5, C6, C7, C8, T1", "Anterior primary rami exiting between scalene muscles"],
    ["Trunks", "Upper (C5+C6)  |  Middle (C7)  |  Lower (C8+T1)", "Above clavicle (supraclavicular)"],
    ["Divisions", "Anterior (flexors) & Posterior (extensors)\nfrom each trunk", "No named terminal branches at this level"],
    ["Cords", "Lateral  |  Posterior  |  Medial\n(named relative to axillary artery)", "Below clavicle (infraclavicular)"],
    ["Branches", "Musculocutaneous, Axillary, Radial, Median, Ulnar\n(+ many smaller named branches)", "Terminal nerves of the upper limb"],
]
story += table(plexus_data, col_widths=[30*mm, 85*mm, 52*mm])

story += H2("Pre-divisional Branches (frequently tested in isolation)")
pre_data = [
    ["Nerve", "Origin", "Muscle(s)", "Injury Sign"],
    ["Long thoracic n.", "C5, C6, C7 (roots)", "Serratus anterior", "Winged scapula; arm can't raise >90°"],
    ["Dorsal scapular n.", "C5 (root)", "Rhomboids + Levator scapulae", "Scapula not retracted; winging (medial)"],
    ["Suprascapular n.", "Upper trunk (C5, C6)", "Supraspinatus + Infraspinatus", "Weak abduction initiation + external rotation"],
    ["Nerve to subclavius", "Upper trunk (C5, C6)", "Subclavius", "Clinically silent (rarely tested)"],
    ["Phrenic nerve (C3-5)", "Root level (C3–5)", "Diaphragm", "Elevated hemidiaphragm — marker of root avulsion"],
]
story += table(pre_data, col_widths=[38*mm, 32*mm, 42*mm, 55*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 2 – ERB'S PALSY
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("2. Erb's Palsy (Upper Trunk Injury — C5, C6)")

story += H2("Mechanism & Causes")
story += bullets([
    "<b>Neonatal:</b> Shoulder dystocia during difficult vaginal delivery — forced depression of shoulder with lateral head flexion",
    "<b>Adult:</b> Motorcycle accident, glenohumeral dislocation — sudden shoulder depression / traction",
    "<b>Iatrogenic:</b> Improper arm positioning under anaesthesia",
])

story += H2("Muscles Lost (C5–C6 innervated)")
story += bullets([
    "Deltoid (abduction lost)",
    "Biceps brachii (elbow flexion + forearm supination lost)",
    "Supraspinatus (abduction initiation lost)",
    "Infraspinatus + Teres minor (external rotation lost)",
    "Brachioradialis (partial elbow flexion loss)",
    "Wrist extensors (partially affected)",
])

story += H2("Classic Posture")
story += P("<b>Waiter's Tip / Bellman's Tip:</b> Arm hangs adducted and internally rotated at the side, "
           "elbow extended, forearm pronated, wrist slightly flexed. <b>Finger and hand movements are "
           "relatively spared</b> (key differentiating point — rules out complete plexus injury).")

story += H2("Prognosis")
story += bullets([
    "Over <b>90% of neonatal cases</b> resolve by 3 months of age",
    "<b>Biceps function at 3 months = the key prognostic indicator</b>",
    "If biceps not recovered by 3–6 months → surgical exploration ± nerve grafting considered",
    "Severity grading: neuropraxia (best) → axonotmesis → neurotmesis (worst)",
])
story += Tip("Erb's palsy is ~20 times more common than Klumpke's palsy.")
story += sp(2)

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 3 – KLUMPKE'S PALSY
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("3. Klumpke's Palsy (Lower Trunk Injury — C8, T1)")

story += H2("Mechanism & Causes")
story += bullets([
    "Forcible <b>hyperabduction</b> of the arm — grabbing a branch during a fall",
    "<b>Pancoast tumour</b> (apical lung carcinoma) invading the lower plexus",
    "Thoracic outlet syndrome (compression between clavicle and 1st rib)",
    "Sudden upward traction on the arm",
])

story += H2("Muscles Lost (C8–T1 innervated)")
story += bullets([
    "All intrinsic hand muscles: interossei, lumbricals, thenar + hypothenar groups",
    "Flexor digitorum profundus to ring + little (C8 component)",
    "Wrist/finger flexors (partial)",
])

story += H2("Classic Posture & Signs")
story += bullets([
    "<b>Claw hand:</b> MCP hyperextension (intrinsics lost) + IP joint flexion (long flexors intact)",
    "Thenar and hypothenar wasting",
    "Sensory loss on medial arm, medial forearm, and ulnar aspect of hand",
    "<b>Depressed / absent finger flexor reflex (C8–T1)</b>",
])

story += H2("Horner's Syndrome Association")
story += P("When <b>T1 root is injured proximal to the sympathetic trunk</b>, sympathetic fibres "
           "destined for the superior cervical ganglion are interrupted → "
           "<b>ipsilateral ptosis + miosis + anhidrosis</b>.")
story += Tip("Presence of Horner's syndrome in a claw hand patient = preganglionic T1 root "
             "lesion (not just peripheral ulnar/median neuropathy).")

story += H2("Erb's vs. Klumpke's — Comparison")
comp_data = [
    ["Feature", "Erb's Palsy", "Klumpke's Palsy"],
    ["Roots", "C5–C6", "C8–T1"],
    ["Trunk", "Upper trunk", "Lower trunk"],
    ["Classic cause", "Shoulder dystocia / depression", "Hyperabduction traction"],
    ["Classic posture", "Waiter's tip", "Claw hand"],
    ["Hands/fingers", "Spared (main differentiator)", "Affected (main deficit)"],
    ["Shoulder/elbow", "Affected (main deficit)", "Spared"],
    ["Horner's syndrome", "No", "Yes (if T1 proximal injury)"],
    ["Frequency", "Common (~20× more frequent)", "Rare"],
    ["Prognosis", ">90% neonatal resolution at 3m", "Less predictable"],
]
story += table(comp_data, col_widths=[38*mm, 60*mm, 60*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 4 – RADIAL NERVE
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("4. Radial Nerve Injuries")

story += H2("Course of the Radial Nerve (High-Yield)")
story += bullets([
    "Arises from <b>posterior cord</b> (C5–C8, T1)",
    "Exits axilla → enters <b>spiral groove (radial groove)</b> of humerus posterolaterally",
    "Winds around the lateral humerus → enters forearm between brachialis and brachioradialis",
    "Splits at the radial tunnel into: <b>superficial branch</b> (sensory only) and "
    "<b>posterior interosseous nerve / PIN</b> (motor only)",
])

story += H2("A. Axillary / Proximal Injury — Crutch Palsy")
story += bullets([
    "<b>Cause:</b> Improper axillary crutch use — compresses nerve in axilla",
    "<b>Signs:</b> Wrist drop + finger drop + <b>triceps weakness</b> + absent triceps reflex",
    "Sensory loss: dorsolateral hand + posterior forearm + lateral arm",
])

story += H2("B. Spiral Groove Injury — Saturday Night Palsy / Humeral Shaft Fracture")
story += bullets([
    "<b>Saturday night palsy:</b> Patient falls asleep drunk with arm over chair/bench — "
    "compression in spiral groove. Also 'Honeymoon palsy' (arm over partner's shoulder).",
    "<b>Humeral shaft fracture:</b> ~22% of mid-shaft humeral fractures injure the radial nerve",
    "<b>Key sign: Wrist drop</b> (weakness of wrist + finger extensors)",
    "Triceps is <b>spared</b> (branches off before spiral groove in most cases)",
    "Sensory loss: dorsal lateral hand (superficial branch territory)",
])
story += Warn("Wrist drop causes mechanical disadvantage. Testing interossei with wrist "
              "dropped may show false ulnar weakness. Fix: place palm flat on a surface, then retest.")

story += H2("Prognosis & Management")
story += bullets([
    "Most humeral shaft radial nerve injuries are <b>neuropraxias</b> — spontaneous resolution 60–92%",
    "Saturday night palsy (demyelinative): recovery typically within <b>6–8 weeks</b>",
    "Axon-loss injuries: slower but most eventually recover",
    "Management: wrist splint at ~60° dorsiflexion while awaiting recovery; EMG at 6–8 weeks",
    "Surgical exploration if no recovery by 3–4 months, or if nerve entrapped in complex fracture",
])

story += H2("C. Posterior Interosseous Nerve (PIN) — Radial Tunnel Syndrome")
story += bullets([
    "<b>Cause:</b> Radial head fracture, lipoma/ganglion at radial tunnel, Monteggia fracture, "
    "repetitive forearm rotation",
    "PIN is a <b>purely motor</b> branch — NO sensory loss",
    "ECRL is spared (branches before PIN) → wrist extends but <b>deviates radially</b>",
    "Finger extension lost; brachioradialis + triceps intact",
])

pin_data = [
    ["Feature", "Spiral Groove Injury", "PIN Injury (radial tunnel)"],
    ["Triceps", "Spared (usually)", "Spared"],
    ["Wrist extension", "Lost (wrist drop)", "Present but radially deviated (ECRL works)"],
    ["Finger extension", "Lost", "Lost"],
    ["Sensory loss", "Dorsal lateral hand", "NONE (purely motor)"],
    ["Brachioradialis", "Intact", "Intact"],
    ["Classic cause", "Humeral shaft fracture", "Radial head Fx / Monteggia Fx"],
]
story += table(pin_data, col_widths=[38*mm, 65*mm, 55*mm])

story += Tip("Finger drop without sensory loss = PIN injury. Wrist drop with sensory loss = spiral groove injury.")

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 5 – MEDIAN NERVE
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("5. Median Nerve Injuries")

story += H2("A. High Median Nerve (Above Elbow) — Supracondylar Fracture")
story += bullets([
    "<b>Classic paediatric scenario:</b> Supracondylar fracture of humerus (anterior fragment injures median nerve)",
    "Also: dislocation of elbow, stab wounds to arm",
])
story += P("<b>Muscles lost:</b>")
story += bullets([
    "Pronator teres, pronator quadratus (pronation weak)",
    "FCR, palmaris longus (wrist flexion weak)",
    "FDS (all fingers)",
    "FDP to index + middle fingers (AIN territory)",
    "FPL (AIN territory)",
    "LOAF muscles of hand (see CTS below)",
])

story += P("<b>Key sign: Hand of Benediction / Preacher's Hand</b> — when patient ATTEMPTS to make "
           "a fist: index and middle fingers remain extended (FDP-1,2 + FPL paralysed). "
           "Ring + little fingers can flex (FDP-3,4 from ulnar nerve intact).")
story += P("<b>Sensory loss:</b> Lateral 3.5 fingers + lateral palm (not thenar eminence — "
           "palmar cutaneous branch exits above wrist).")

story += H2("B. Anterior Interosseous Nerve (AIN) Syndrome")
story += bullets([
    "AIN is a purely <b>motor</b> branch of the median nerve in the forearm",
    "Causes: forearm trauma, fibrous band entrapment",
    "Muscles lost: FDP to index+middle, FPL, pronator quadratus",
    "<b>NO sensory loss</b>",
    "<b>Test:</b> Ask patient to make 'OK' circle with thumb and index finger — "
    "unable to form a circle, shows 'pinch sign' instead",
])
story += Tip("AIN palsy = can't make the OK sign. No sensory loss. Purely motor.")

story += H2("C. Carpal Tunnel Syndrome (CTS) — Wrist Level")
story += P("<b>Most common nerve compression syndrome in the body.</b> Median nerve compressed "
           "under the flexor retinaculum.")
story += P("<b>Classic scenario:</b> Middle-aged woman, bilateral hand tingling worse at night, "
           "relieved by shaking the hand (<b>flick sign</b>).")
story += P("<b>Associations:</b> Pregnancy, hypothyroidism, diabetes, acromegaly, rheumatoid "
           "arthritis, repetitive wrist use, Colles' fracture, obesity.")

story += P("<b>Muscles lost (LOAF mnemonic):</b>")
story += bullets([
    "<b>L</b>umbricals 1 & 2",
    "<b>O</b>pponens pollicis",
    "<b>A</b>bductor pollicis brevis (best single muscle to test)",
    "<b>F</b>lexor pollicis brevis (superficial head)",
])

story += P("<b>Key spared functions at wrist level:</b>")
story += bullets([
    "Wrist flexion (FCR branches off proximal to tunnel)",
    "Thenar eminence sensation (palmar cutaneous branch exits before tunnel)",
    "Index/middle DIP flexion (FDP branches off proximal to tunnel)",
    "<b>No hand of benediction</b> (that requires high lesion)",
])

story += P("<b>Provocative tests:</b>")
story += bullets([
    "<b>Tinel's sign:</b> Tapping over carpal tunnel at wrist → tingling in fingers",
    "<b>Phalen's test:</b> Forced wrist flexion for 60 seconds → paresthesias "
    "(more sensitive than Tinel's)",
    "<b>Reverse Phalen's / Prayer test:</b> Dorsa of hands pressed together (extension) → symptoms",
])
story += Warn("Sensation over the THENAR EMINENCE is SPARED in CTS because the palmar cutaneous "
              "branch of the median nerve exits proximal to the carpal tunnel. A common MCQ trap.")

story += H2("High vs. Wrist Median Nerve — Key Differences")
med_data = [
    ["Feature", "High (Above Elbow)", "Wrist (CTS)"],
    ["Classic cause", "Supracondylar Fx humerus (child)", "Repetitive use / pregnancy / CTS"],
    ["Hand of benediction", "Yes (on attempted fist)", "No"],
    ["Thenar wasting", "Yes (with time)", "Yes (with time — LOAF)"],
    ["Index DIP flexion", "Lost (FDP-1,2 affected)", "Intact (FDP branches off early)"],
    ["Sensory — lateral 3.5 fingers", "Lost", "Lost"],
    ["Thenar eminence sensation", "Lost", "Spared (palmar cutaneous branch)"],
    ["Pronation", "Weak", "Normal"],
    ["Wrist flexion (FCR)", "Weak", "Normal (branches off proximal to tunnel)"],
]
story += table(med_data, col_widths=[46*mm, 58*mm, 58*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 6 – ULNAR NERVE
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("6. Ulnar Nerve Injuries")

story += H2("A. At the Elbow — Cubital Tunnel Syndrome")
story += bullets([
    "<b>Most common cause of ulnar neuropathy</b>",
    "Nerve passes through cubital tunnel behind medial epicondyle (between olecranon and medial epicondyle)",
    "<b>Causes:</b> Medial epicondyle fracture, elbow valgus deformity (tardy ulnar palsy), "
    "repetitive elbow flexion, leaning on elbows",
])

story += P("<b>Muscles lost:</b>")
story += bullets([
    "FCU (ulnar wrist flexion)",
    "FDP to ring + little fingers (DIP flexion lost — digit 4 and 5)",
    "All interossei (finger abduction/adduction)",
    "Hypothenar muscles (ADM, FDM, ODM)",
    "Adductor pollicis + deep head FPB",
    "Lumbricals 3 & 4 (ring + little finger MCP flexion)",
])

story += P("<b>Signs:</b>")
story += bullets([
    "<b>Claw hand</b> of ring + little fingers (MCP hyperextension + IP flexion)",
    "<b>Froment's sign:</b> Ask patient to hold paper between thumb and index; adductor pollicis "
    "is weak, so patient compensates by flexing thumb IP (using FPL — median nerve). "
    "Positive = thumb IP flexes during key pinch.",
    "<b>Wartenberg's sign:</b> Little finger stays abducted during attempted adduction (EDQ unopposed "
    "by paralysed 3rd volar interosseous)",
    "Sensory loss: ulnar 1.5 fingers, medial palm, dorsum of ulnar hand",
    "Hypothenar + interosseous wasting (guttering between metacarpals)",
])

story += H2("B. At the Wrist — Guyon's Canal")
story += bullets([
    "<b>Classic scenario:</b> Cyclist (handlebar palsy), hook of hamate fracture, chronic hammering",
    "FCU and FDP to ring/little are <b>SPARED</b> (these branches off above the wrist)",
    "If only deep motor branch compressed: <b>motor deficit only, no sensory loss</b>",
    "Interossei + hypothenar + adductor pollicis weak",
    "Claw hand more pronounced than elbow-level injury (see Ulnar Paradox below)",
])

story += H2("The Ulnar Paradox — DIRECT FMGE MCQ")
story += P("<b>Question:</b> In which level of ulnar nerve injury is the claw hand deformity MORE pronounced?")
story += P("<b>Answer: Distal (wrist-level) injury produces a MORE pronounced claw than proximal (elbow-level) injury.</b>")
story += P("<b>Why?</b>")
story += bullets([
    "<b>High ulnar lesion (elbow):</b> FDP to ring + little is ALSO paralysed. "
    "Without FDP, the fingers cannot fully flex into the claw — IP joints cannot "
    "pull down forcefully. Deformity is LESS obvious.",
    "<b>Low ulnar lesion (wrist):</b> FDP to ring + little is INTACT. "
    "Long flexors pull IP joints into strong flexion while lumbricals are still out → "
    "MORE pronounced claw.",
])
story += Warn("The Ulnar Paradox: The more DISTAL the ulnar lesion, the MORE PRONOUNCED the "
              "claw hand. This is counter-intuitive and a favourite FMGE trick question.")

story += H2("Elbow vs. Wrist Ulnar Nerve — Key Differences")
ul_data = [
    ["Feature", "Elbow (Cubital Tunnel)", "Wrist (Guyon's Canal)"],
    ["FCU", "Weak", "Normal"],
    ["FDP ring/little (DIP flex)", "Weak", "Normal"],
    ["Interossei + hypothenar", "Weak", "Weak"],
    ["Adductor pollicis", "Weak", "Weak"],
    ["Froment's sign", "Positive", "Positive"],
    ["Sensory loss", "Ulnar 1.5 fingers + medial palm + dorsum", "Variable; none if deep branch only"],
    ["Claw hand severity", "LESS pronounced (paradox)", "MORE pronounced (paradox)"],
    ["Classic cause", "Medial epicondyle Fx / elbow lean", "Cyclist / hamate Fx"],
]
story += table(ul_data, col_widths=[50*mm, 57*mm, 55*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 7 – OTHER KEY NERVES
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("7. Other High-Yield Nerves")

story += H2("A. Axillary Nerve")
story += bullets([
    "<b>Origin:</b> Posterior cord (C5, C6)",
    "<b>Course:</b> Winds around <b>surgical neck of humerus</b> with posterior circumflex humeral artery",
    "<b>Classic injury:</b> Fracture of surgical neck of humerus OR anterior shoulder dislocation "
    "(most common joint dislocation in the body)",
    "<b>Muscles:</b> Deltoid + Teres minor",
    "<b>Signs:</b> Loss of shoulder abduction (cannot abduct >15–20°), loss of external rotation",
    "<b>Sensory:</b> 'Regimental badge area' — circular patch on lateral upper arm/shoulder",
])
story += Warn("C5 radiculopathy also weakens deltoid AND biceps. Axillary nerve injury spares "
              "biceps (musculocutaneous territory). Use sensory distribution + biceps strength to differentiate.")

story += H2("B. Long Thoracic Nerve (C5, C6, C7)")
story += bullets([
    "<b>Only muscle:</b> Serratus anterior",
    "<b>Function:</b> Holds scapula against chest wall + protracts scapula + rotates glenoid "
    "upward (allows arm elevation above 90°)",
    "<b>Signs:</b> Winged scapula (medial border protrudes when pushing against wall); "
    "arm cannot be raised past 90°",
    "<b>Causes:</b> Mastectomy / axillary lymph node dissection, carrying heavy loads "
    "('rucksack paralysis'), viral neuritis, stab wound to lateral chest",
])
story += Warn("Trapezius palsy (spinal accessory nerve CN XI) also causes winging — but winging "
              "is worst when the arm is RAISED. Serratus anterior winging is worst when PUSHING. "
              "Trapezius palsy also drops the shoulder.")

story += H2("C. Musculocutaneous Nerve")
story += bullets([
    "<b>Origin:</b> Lateral cord (C5, C6, C7)",
    "<b>Muscles:</b> Biceps brachii, brachialis, coracobrachialis",
    "<b>Injury:</b> Lateral cord lesion, shoulder dislocation, axilla stab wound",
    "<b>Signs:</b> Weak elbow flexion + weak forearm supination + absent biceps reflex",
    "<b>Sensory:</b> Lateral forearm (becomes lateral cutaneous nerve of forearm)",
    "<b>Distinguish from C5/C6 root:</b> Musculocutaneous lesion has lateral forearm sensory "
    "loss; root lesion has broader dermatomal involvement",
])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 8 – HAND POSTURES
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("8. Classic Hand Postures — Named Deformities")

posture_data = [
    ["Posture Name", "Nerve / Level", "When Seen", "Mechanism"],
    ["Waiter's Tip / Bellman's Tip", "Upper trunk C5-C6 (Erb's)", "At rest (passive)",
     "Arm: adducted, int. rotated; elbow extended; wrist flexed"],
    ["Claw Hand (ring + little)", "Ulnar nerve (any level)", "At rest or on finger extension",
     "MCP hyperextension + IP flexion; worse distally (ulnar paradox)"],
    ["Wrist Drop", "Radial nerve (spiral groove / axilla)", "At rest",
     "Wrist + finger extensors paralysed; gravity causes wrist to fall"],
    ["Hand of Benediction / Preacher's Hand", "Proximal median nerve (above elbow)",
     "When ATTEMPTING to make a fist",
     "Index + middle stay extended (FDP-1,2 + FPL lost); ring + little flex normally"],
    ["Pope's Blessing / Oath Hand", "Proximal median nerve", "At rest",
     "Index + middle extended at rest (same nerve, different context of description)"],
    ["Ape Hand / Simian Hand", "Chronic median + ulnar combined", "At rest (late stage)",
     "Thenar + hypothenar wasting; thumb falls into plane of palm; no opposition"],
    ["OK Sign inability", "AIN (median branch)", "On attempted OK sign",
     "FDP-1 + FPL weak; cannot form circle; makes a 'pinch' instead"],
]
story += table(posture_data, col_widths=[44*mm, 42*mm, 30*mm, 46*mm])

story += Warn("Claw hand vs. Hand of Benediction: Claw = at REST or on extension attempt "
              "(ulnar). Benediction = when MAKING A FIST (proximal median). Examinees frequently "
              "swap these two.")

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 9 – PREGANGLIONIC vs POSTGANGLIONIC
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("9. Preganglionic vs. Postganglionic Brachial Plexus Injury")

story += P("This distinction determines surgical outcome and is directly tested in FMGE.")

pg_data = [
    ["Feature", "Preganglionic (Root Avulsion)", "Postganglionic"],
    ["Site of injury", "Nerve root avulsed from spinal cord\n(proximal to DRG)", "Nerve torn distal to dorsal root ganglion"],
    ["Histamine test", "Axon flare PRESENT\n(DRG + axon to skin still intact)", "Axon flare ABSENT"],
    ["Horner's syndrome", "Present (if C8–T1 avulsion)", "Usually absent"],
    ["Paraspinal muscles (EMG)", "Denervated", "Normal"],
    ["SSEP / sensory NCS", "Preserved (DRG intact)", "Absent"],
    ["Cervical MRI/myelogram", "Pseudomeningocele", "Normal"],
    ["Phrenic nerve palsy", "Often co-exists (elevated hemidiaphragm)", "Usually absent"],
    ["Surgical repair", "NOT possible (no proximal stump); nerve transfer only", "Possible — nerve grafting / repair"],
    ["Prognosis", "Worse", "Better"],
]
story += table(pg_data, col_widths=[46*mm, 65*mm, 51*mm])

story += Tip("Preganglionic = root is torn from cord = no surgical repair possible. "
             "Postganglionic = distal to DRG = repair/grafting feasible.")

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 10 – ANATOMICAL SNUFFBOX
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("10. Anatomical Snuffbox & Scaphoid Fracture")

story += H2("Anatomy of the Anatomical Snuffbox")
story += P("Triangular depression on the posterolateral side of the wrist and base of 1st "
           "metacarpal, visible when the thumb is extended.")

snuff_data = [
    ["Border / Structure", "What forms it"],
    ["Lateral (radial) border", "Tendons of Abductor Pollicis Longus (APL) + Extensor Pollicis Brevis (EPB)"],
    ["Medial (ulnar) border", "Tendon of Extensor Pollicis Longus (EPL)"],
    ["Floor", "Scaphoid + Trapezium + distal ECRL + ECRB tendons"],
    ["Roof", "Skin"],
    ["Contents — Radial artery", "Passes obliquely through the floor, deep to tendons, adjacent to scaphoid"],
    ["Contents — Superficial radial nerve", "Passes subcutaneously over the roof"],
    ["Contents — Cephalic vein", "Origin from dorsal venous arch crosses over the roof"],
]
story += table(snuff_data, col_widths=[55*mm, 107*mm], hdr_rows=1)

story += H2("Clinical Significance — Scaphoid Fracture")
story += bullets([
    "<b>Mechanism:</b> Fall on outstretched hand (FOOSH) — forced dorsiflexion",
    "<b>Most common carpal bone fracture</b>",
    "Up to <b>30–40% of scaphoid fractures are X-ray negative</b> on initial assessment",
    "Anatomical snuffbox tenderness: sensitivity <b>87–100%</b>, specificity 3–98% "
    "(very sensitive, not specific — use to rule OUT)",
    "Combination (snuffbox tenderness + scaphoid tubercle tenderness + compression test "
    "within 24 h): sensitivity <b>100%</b>, specificity <b>74%</b>",
])

story += Warn("A normal X-ray DOES NOT rule out a scaphoid fracture. Treat snuffbox "
              "tenderness after FOOSH as scaphoid fracture until proven otherwise. "
              "Immobilise in thumb spica splint; repeat X-ray at 10–14 days or proceed to CT/MRI.")

story += H2("Why Scaphoid Fractures Are Dangerous")
story += bullets([
    "Blood supply enters the scaphoid <b>distally</b> (distal pole) via the radial artery",
    "Proximal pole depends on <b>retrograde flow</b>",
    "Waist fractures disrupt this supply → <b>avascular necrosis (AVN) of proximal pole</b> if missed",
    "Proximal pole fractures have highest risk of AVN (~40%); waist fractures ~10–15%",
])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 11 – FRACTURE-TO-NERVE INJURY MAPPING
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("11. Fracture-to-Nerve Injury Mapping (FMGE Favourite)")

fx_data = [
    ["Fracture / Dislocation", "Nerve at Risk", "Key Sign"],
    ["Surgical neck of humerus", "Axillary nerve", "Deltoid weakness + regimental badge sensory loss"],
    ["Mid-shaft (spiral groove) humerus", "Radial nerve", "Wrist drop (22% incidence)"],
    ["Supracondylar humerus (child)", "Median nerve / AIN", "Hand of benediction; can't make OK sign"],
    ["Lateral epicondyle humerus", "Radial nerve (PIN)", "Finger drop, no sensory loss"],
    ["Medial epicondyle / posterior elbow dislocation", "Ulnar nerve", "Claw (ring+little), Froment's sign"],
    ["Monteggia fracture (proximal ulna + radial head dislocation)", "PIN (radial nerve deep branch)", "Finger drop, no sensory loss"],
    ["Colles' fracture (distal radius)", "Median nerve / CTS", "Thenar wasting, carpal tunnel symptoms"],
    ["Hook of hamate fracture", "Ulnar nerve (Guyon's canal)", "Intrinsic weakness, variable sensory loss"],
    ["Anterior shoulder dislocation", "Axillary nerve", "Deltoid weakness + regimental badge area"],
    ["Glenohumeral dislocation (broad)", "Axillary nerve + brachial plexus (upper trunk)", "Combined — Erb's + axillary features"],
    ["1st rib / cervical rib (thoracic outlet)", "Lower trunk C8-T1", "Klumpke's signs ± Horner's"],
]
story += table(fx_data, col_widths=[58*mm, 48*mm, 56*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 12 – MASTER QUICK-REFERENCE TABLE
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("12. Master Quick-Reference — All Upper Limb Nerves")

master_data = [
    ["Nerve", "Level of Injury", "Mechanism", "Motor Loss", "Sensory Loss", "Named Sign"],
    ["Upper trunk C5–C6\n(Erb's palsy)", "Upper trunk", "Birth trauma / shoulder depression",
     "Deltoid, biceps, supraspinatus, wrist ext", "Lateral arm + forearm", "Waiter's tip"],
    ["Lower trunk C8–T1\n(Klumpke's)", "Lower trunk", "Hyperabduction traction",
     "Intrinsics, wrist/finger flexors", "Medial arm, ulnar hand", "Claw hand + Horner's"],
    ["Radial nerve", "Axilla (crutch palsy)", "Axillary crutch",
     "Wrist + finger ext + TRICEPS", "Dorsolateral hand + post forearm", "Wrist drop + triceps absent"],
    ["Radial nerve", "Spiral groove", "Humeral shaft Fx / sleep compression",
     "Wrist + finger ext (triceps SPARED)", "Dorsal lateral hand", "Wrist drop (Saturday night)"],
    ["PIN (radial)", "Radial tunnel", "Radial head Fx / Monteggia",
     "Finger ext; ECRL spared → radial deviation", "NONE", "Finger drop without sensory loss"],
    ["Median nerve", "Above elbow", "Supracondylar Fx (child)",
     "FDP-1,2; FPL; LOAF; pronation", "Lateral 3.5 fingers + lat palm", "Hand of benediction"],
    ["AIN (median)", "Forearm", "Entrapment / forearm trauma",
     "FDP-1,2; FPL only", "NONE", "Can't make OK sign"],
    ["Median nerve", "Wrist (CTS)", "Repetitive use / pregnancy etc.",
     "LOAF only", "Lateral 3.5 fingers (NOT thenar eminence)", "Tinel's + Phalen's; thenar wasting"],
    ["Ulnar nerve", "Elbow (cubital tunnel)", "Medial epicondyle Fx / leaning",
     "FCU, FDP-4,5, intrinsics", "Ulnar 1.5 + med palm + dorsum", "Claw LESS pronounced; Froment's; Wartenberg's"],
    ["Ulnar nerve", "Wrist (Guyon's)", "Cyclist / hamate Fx",
     "Intrinsics (FCU, FDP-4,5 spared)", "None if deep branch only", "Claw MORE pronounced (ulnar paradox)"],
    ["Axillary nerve", "Surgical neck humerus", "Surgical neck Fx / ant dislocation",
     "Deltoid, teres minor", "Regimental badge area", "Shoulder abduction lost"],
    ["Long thoracic n.", "Variable", "Mastectomy / rucksack / viral",
     "Serratus anterior", "None", "Winged scapula; arm can't go >90°"],
    ["Musculocutaneous n.", "Lateral cord / axilla", "Shoulder dislocation / stab",
     "Biceps, brachialis", "Lateral forearm", "Weak elbow flexion + supination"],
]
story += table(master_data, col_widths=[30*mm, 22*mm, 30*mm, 40*mm, 28*mm, 32*mm])

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 13 – FMGE ONE-LINERS
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("13. FMGE High-Yield One-Liners")

one_liners = [
    "Radial nerve = most commonly injured nerve in the upper limb overall (spiral groove vulnerability)",
    "Median nerve = most commonly compressed nerve (CTS is the most common entrapment neuropathy)",
    "Ulnar nerve = most commonly injured nerve AT THE ELBOW (cubital tunnel)",
    "Supracondylar Fx humerus in children → median nerve / AIN injury (anterior fragment)",
    "Posterior elbow dislocation → ulnar nerve injury",
    "Anterior shoulder dislocation → axillary nerve injury (most common dislocation in the body)",
    "Surgical neck humerus Fx → axillary nerve injury",
    "Mid-shaft humeral Fx → radial nerve (22% incidence; most are neuropraxias)",
    "Monteggia Fx → PIN injury (finger drop, NO sensory loss)",
    "Colles' Fx → median nerve / acute CTS",
    "Hook of hamate Fx → ulnar nerve at Guyon's canal",
    "Winged scapula on wall push → long thoracic nerve (serratus anterior)",
    "Winged scapula on arm elevation → spinal accessory nerve (trapezius)",
    "Horner's + claw hand → preganglionic T1 root avulsion (Klumpke's level)",
    "Horner's + apical lung mass → Pancoast tumour (lower plexus C8–T1 + T1 sympathetics)",
    "Pseudomeningocele on MRI + Horner's → preganglionic root avulsion (no surgical repair possible)",
    "Histamine test flare PRESENT despite anaesthetic skin → preganglionic injury (DRG intact)",
    "Nerve regeneration rate = ~1 mm/day (3 cm/month); recovery takes months to over a year",
    "Biceps function at 3 months = prognostic indicator in neonatal Erb's palsy",
    "AIN test = OK sign; can't make circle = AIN palsy (no sensory loss)",
    "Froment's sign = adductor pollicis palsy (ulnar); compensates with FPL (median)",
    "Wartenberg's sign = 3rd volar interosseous palsy (ulnar); little finger stays abducted",
    "Ulnar paradox: DISTAL lesion → MORE pronounced claw (FDP intact → stronger IP flexion)",
    "CTS spares thenar eminence sensation (palmar cutaneous branch exits proximal to tunnel)",
    "Scaphoid fracture: X-ray negative in 30–40% initially → treat snuffbox tenderness as Fx",
    "Scaphoid blood supply enters DISTALLY → proximal pole at risk for AVN if waist Fx missed",
    "APL + EPB = lateral border of anatomical snuffbox; EPL = medial border",
    "Radial artery + superficial radial nerve + cephalic vein cross the anatomical snuffbox",
]

for i, line in enumerate(one_liners, 1):
    story.append(Paragraph(f"<b>{i}.</b> {line}", S["bullet"]))
story += sp(2)

# ═══════════════════════════════════════════════════════════════════════════════
# SECTION 14 – SCENARIO PATTERN RECOGNITION
# ═══════════════════════════════════════════════════════════════════════════════
story += H1("14. FMGE Scenario Pattern Recognition")

scenario_data = [
    ["Clinical Scenario", "Likely Injury", "Nerve / Level"],
    ["Newborn, shoulder dystocia, arm hangs internally rotated",
     "Erb's palsy", "Upper trunk C5–C6"],
    ["Adult, motorcycle accident, arm hangs + wrist slightly flexed",
     "Erb's palsy", "Upper trunk C5–C6"],
    ["Fall from tree grabbing branch → claw hand",
     "Klumpke's palsy", "Lower trunk C8–T1"],
    ["Klumpke's features + drooping eyelid + small pupil",
     "Klumpke's + Horner's", "Preganglionic T1 root avulsion"],
    ["Apical lung mass + claw hand + Horner's",
     "Pancoast syndrome", "Lower trunk C8–T1 + T1 sympathetics"],
    ["Drunk patient, woke up with wrist drop, no fracture",
     "Saturday night palsy", "Radial nerve, spiral groove"],
    ["Mid-shaft humerus fracture + wrist drop",
     "Radial nerve injury", "Spiral groove (22% of mid-shaft Fx)"],
    ["Radial head fracture + finger drop, NO sensory loss",
     "PIN injury", "Radial nerve deep branch, radial tunnel"],
    ["Child, supracondylar Fx + index/middle can't flex into fist",
     "Median / AIN injury", "High median or AIN"],
    ["Can't make 'OK' sign, no sensory loss",
     "AIN palsy", "Anterior interosseous nerve (median branch)"],
    ["Middle-aged woman, bilateral hand tingling at night, shakes hand for relief",
     "Carpal tunnel syndrome", "Median nerve at wrist"],
    ["Medial epicondyle fracture → ring + little claw + Froment's sign",
     "Ulnar nerve injury", "Cubital tunnel (elbow)"],
    ["Cyclist with weak intrinsics, NO sensory loss",
     "Deep branch ulnar compression", "Guyon's canal (wrist)"],
    ["FOOSH + snuffbox tenderness, normal X-ray",
     "Occult scaphoid fracture", "Treat as fracture; immobilise"],
    ["Surgical neck humerus Fx + deltoid weakness + regimental badge numbness",
     "Axillary nerve injury", "Surgical neck level"],
    ["Mastectomy + arm can't raise past 90° + winged scapula",
     "Long thoracic nerve injury", "Serratus anterior palsy"],
    ["Factory worker, Monteggia fracture + finger drop (no sensory loss)",
     "PIN injury", "Radial nerve deep branch"],
    ["MRI shows pseudomeningocele at C8–T1 + Horner's + no surgical target",
     "Preganglionic root avulsion", "C8–T1 avulsion; nerve transfer only option"],
]
story += table(scenario_data, col_widths=[68*mm, 48*mm, 46*mm])

# ── Footer note ───────────────────────────────────────────────────────────────
story += sp(4)
story += hr()
story.append(Paragraph(
    "<b>Sources:</b> Gray's Anatomy for Students | Miller's Review of Orthopaedics 9e | "
    "Neuroanatomy through Clinical Cases 3e | Localization in Clinical Neurology 8e | "
    "Schwartz's Principles of Surgery 11e | Bailey &amp; Love 28e | "
    "THIEME Atlas of General Anatomy &amp; Musculoskeletal System | "
    "Rockwood &amp; Green's Fractures in Adults 10e (2025) | Rosen's Emergency Medicine",
    S["footer"]
))

# ── Build ─────────────────────────────────────────────────────────────────────
doc.build(story)
print(f"PDF written to: {OUTPUT}")

cd /home/daytona/workspace/brachial-plexus-pdf && python3 generate_pdf.py 2>&1

ls -lh /home/daytona/workspace/brachial-plexus-pdf/